1. Field of the Invention
The present invention relates to a granular agent for a ruminant and containing a physiologically active substance, and a production method thereof. More specifically, it relates to a granular agent for a ruminant in which a physiologically active substance usually fed with, for example, an animal feed, is protected from the action of microorganisms present in a rumen of a ruminant and is digested and absorbed in an abomasum and downstream thereof, and a production method thereof.
2. Description of the Related Art
For example, in ruminants such as cattles and sheep, a vriety of microorganisms are present in a rumen and, therefore, cellulose and other components, which cannot be inherently digested in the higher animals, are utilized with the assistance of the action of the microorganisms. However, when physiologically active substances such as amino acids and proteins are orally fed, most of those substances are decomposed by the organism in a rumen to lose their physiological activities and, therefore, these physiologically active substances cannot be effectively utilized.
Thus, a so-called rumen-by-pass granular agent, i.e., an agent which is not solubilized in a rumen and is dissolved and absorbed in an abomasum and downstream thereof, is important to effectively utilize physiologically active substances in ruminants. Various such granular agents have been developed and utilized in the fields of, for example, animal feed, nutrients, and drugs.
The conventional rumen-by-pass agents for ruminants are generally produced by coating physiologically active substances with protective substances. However, none the granulating techniques heretofore proposed have satisfactory effects (e.g., granule strength, particle size, and solubility).
That is, as the granulating techniques for the granular agents, melt granulation methods, extrusion granulation methods, compression granulation methods, tumbling granulation methods, spary cooling methods, fluidized bed granulation methods and the like are generally utilized. Furthermore, a large amount of binder is used for further controlling the solubility according to spray cooling method and extrusion granulating method. On the other hand according to tumbling granulation method and fluidized bed granulation method a relatively small amount of binders is used. However, these granulating methods have the following problems.